We've been trying to setup Guest and External Access for our tenant as well as other approved tenants. We've been able to communicate with users from other tenants, but are running into some issues. In order to keep this simple, our tenant will be called A and the other tenant will be called B.
Tenant A users can send Team messages with Tenant B users with no issues and Tenant B users can respond with no issues. But if Tenant B tries to initiate a conversation with Tenant A users, it returns a not available message and Tenant A users will not be notified. This usually happens to users that have already started conversations. We've been racking our brains trying to figure this out. Does anyone have a solution?